Wave Mechanics Question 766
Question: In a sonometer wire, the tension is maintained by suspending a 50.7 kg mass from the free end of the wire. The suspended mass has a volume of 0.0075 m3. The fundamental frequency of the wire is 260 Hz. If the suspended mass is completely submerged in water, the fundamental frequency will become (take g = 10 ms?2)
[KCET 2001]
Options:
A) 240 Hz
B) 230 Hz
C) 220 Hz
D) 200 Hz
Show Answer
Answer:
Correct Answer: A
Solution:
$ n=\frac{p}{2l}\sqrt{\frac{T}{m}}\propto \sqrt{T} $
Therefore $ \frac{n _{1}}{n _{2}}=\sqrt{\frac{T _{1}}{T _{2}}} $
Therefore $ \frac{260}{n _{2}}=\sqrt{\frac{50.7g}{(50.7-0.0075\times 10^{3})g}} $
Therefore $ n _{2}\approx 240 $
BETA
